Conventionally, a fitting detection structure of a connector having a first housing and a second housing which are formed to be fitted to each other is known. A detection terminal having a pair of contact portions is supported by the first housing in conjunction with the fitting operation, and a pair of mating terminals electrically connectable to the pair of contact portions of the detection terminals are supported by a second housing (See, for example, Patent Document 1).
In the fitting detection structure, when the pair of mating terminals are brought into contact with the pair of contact portions of the detection terminal and guided in a case that the both housings are fitted, a detection circuit connected to the pair of mating terminals outputs a detection signal to detect that both housings have reached the mated state.